The present disclosure disclosed herein relates to an apparatus for treating a substrate and a method for treating a substrate, and more particularly, to a rotatable spin head supporting a substrate in a process such as a semiconductor process, and an apparatus and a method for treating the substrate using the spin head.
A semiconductor process includes a process of etching or cleaning thin layers, foreign substances, and particles on a wafer. Such an etching or cleaning process is performed by placing a wafer on a spin head such that a surface of a pattern faces upward or downward, rotating the spin head at a high speed, and supplying process liquid on the wafer. The spin head is provided with chuck pins that support the lateral portion of a wafer to prevent the wafer from moving in the lateral direction of the spin head when the wafer is rotated. The chuck pins move between waiting positions providing a space where a substrate is placed when the substrate is loaded on or unloaded from the spin head and supporting positions contacting the lateral portion of the substrate when the substrate placed on the spin head is rotated and a process is performed. Thus, the space provided between the chuck pins placed at the waiting positions is greater than the space provided between the chuck pins placed at the supporting positions.
In general, when chuck pins are placed at supporting positions to support a substrate, centrifugal force due to the rotation of the substrate is applied to the chuck pins toward waiting positions. When the chuck pins are moved to the waiting positions by centrifugal force during a process, it is difficult for the chuck pins to stably support the substrate, thus causing defects in products.
In addition, a spin head is provided with chuck pins that are classified into two groups, and the group of the chuck pins supporting a substrate is changed during a process. In this case, three chuck pins are typically provided to each of the groups. However, when the three chuck pins support a substrate with one of the three chuck pins being disposed in a notch of the substrate, the substrate are supported substantially by the two chuck pins. For this reason, it is difficult for the chuck pins to stably support the substrate, thus causing defects in products.